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Fencer Vulns
medium 6.2

CVE-2026-71430 json

node-re2: String.prototype.replace(re2, template) aborts the Node process (uncatchable ToLocalChecked on empty MaybeLocal) when the result exceeds V8's max string length

published 2026-08-06 3 mo ago modified 2026-10-24 15 d ago also GHSA-8hcv-x26h-mcgp , EUVD-2026-54159

cvss
6.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

node-re2 provides RE2 regular expression bindings for Node.js. Prior to version 1.25.1, the WrappedRE2::Replace function built its replacement result and passed it to V8 using ToLocalChecked without checking for the empty MaybeLocal that V8 returns when the resulting string or buffer exceeds V8's maximum string length. When a global replace uses an output amplifying replacement template, the result can grow quadratically with the input size, and once the result exceeds V8's maximum string length, the unchecked ToLocalChecked call causes a fatal, uncatchable process abort instead of a catchable exception. This issue is fixed in version 1.25.1.

Patch / fix

  • npm re2 1.25.1
  • node-re2 Debian 14 1.26.1+~cs1.7.0-1

debian advisories DEBIAN-CVE-2026-71430

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-71430 updated cvss 7.5

node-re2: node-re2: Denial of Service due to excessive string length in replacements

  • Red Hat Enterprise Linux AI (RHEL AI) 3 re2 20211101-5.el9ai
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/uhop/node-re2/security/advisories/GHSA-8hcv-x26h-mcgp referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 6.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm re2
<1.25.1
1.25.1

Affected products

  • uhop node-re2

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.